Electronic anesthesia delivery apparatus

ABSTRACT

An electronic anesthesia delivery apparatus having a chassis including a first anesthetic agent chamber and a second anesthetic agent chamber, each of the first and second chambers including an anesthetic agent therein. At least one electronically controlled valve is in fluid communication with each of the first agent chamber and the second agent chamber and an oxygen source. The oxygen source is in fluid communication with each of the at least one electronically controlled valves. A touchscreen graphic display having controls corresponding to each of the at least one electronically controlled valves for controlling flow rate and concentration of anesthesia.

CROSS REFERENCES TO RELATED APPLICATIONS

None.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

None.

REFERENCE TO SEQUENTIAL LISTINGS, ETC

None.

BACKGROUND

1. Field of the Invention

The present invention provides an anesthesia delivery apparatus. Morespecifically, the present invention comprises an electronic anesthesiadelivery apparatus for controlling delivery of at least two anestheticagents from at least two respective diffusers to a patient.

2. Description of the Related Art

Standard anesthesia delivery machines utilize a plurality of mechanicalcomponents to deliver a measured amount of anesthesia to a patient, forexample, an animal. Many of these standard devices include an oxygenflow meter, a pressure gauge, and a vaporizer. Such vaporizers typicallyinclude a canister housing an anesthetic agent and a wicking material.As the wicking material absorbs the anesthetic agent, oxygen flows bythe wicking material and vaporizes the anesthetic agent molecules fordelivery to the patient. In order to vary the delivery percentage ofdrug to the user, an oxygen control valve is opened or closed in orderto vary the amount of oxygen flowing past the wicking material, thusvarying the percentage of drug delivered to the patient. A mechanicalthermostat regulates the division of oxygen flow within the vaporizer inorder to compensate for changes in temperature of the anesthetic agentdue to the vaporizing process, or due to change in room temperature

One problem associated with the above mentioned traditional vaporizersis that being mechanical, the vaporizer loses accuracy due to wear ofthe internal mechanical thermostats and loss of efficiency of thewicking material. Therefore the vaporizer must be periodically removedand sent to a repair facility for overall. Another problem is thespecifications for vaporizers on the market today. Most have accuracy of+/−15% of the percentage flow rate indicated and others have accuracyspecification of +/−20% of the indicated percentage flow rate ofanesthesia. Yet another problem is their up-front expense and theinability to be easily converted to new drug types. In order to convertto a new drug type, the wicking material must be replaced requiringremoval of the canister from the machine. Such design is not costeffective. It would be preferable to design a device wherein anestheticagent may be replaced rather than requiring replacement of the entirecanister and the wicking material.

Another weakness of the traditional vaporizers is their percentage ofanesthesia output with respect to flow over a time period. Initially theoutput percentage is low at start up flows and increases to the outputdial setting then holds steady at about +/−15 to 20% (percent) of a dialsetting through oxygen flows of up to about 7 to 10 liters of flow.After that point the output percentage decreases due to the higherflowrates of oxygen flowing through the vaporizer.

Another problem is that physicians must manually operate mechanicalvalves and dials on anesthesia machines. Typically, these valves must beoperated at different locations of the anesthesia machine. This isdifficult and requires the physician or assistant to look to differentlocations of the delivery apparatus to make adjustments. Further, thephysician or assistant must try to compensate for temperature and flowsbased on information provided by the gauges. It would be preferable todesign a device which may be controlled by a single interface and whichcompensates for operating conditions electronically.

Given the foregoing, it will be appreciated that an apparatus isrequired which overcomes the aforementioned difficulties anddeficiencies.

SUMMARY OF THE INVENTION

According to one embodiment, an electronic anesthesia deliveryapparatus, comprises a chassis having at least one anesthetic vaporizer,an oxygen input port in flow communication with the at least oneanesthetic vaporizer, and a touchscreen display mounted to the chassiscomprising an electronic touchscreen display for controlling an oxygenflow rate to the at least one anesthetic vaporizer and concentration ofanesthetic gas delivered to a patient.

A breathing circuit is defined between a patient and the anesthesiadelivery apparatus. The electronic anesthesia delivery apparatus furthercomprises an oxygen source in fluid communication with the oxygen inputport of the anesthesia delivery apparatus. Electronically controlledvalves selectively control flow of oxygen from the source to the firstand second chambers. A first port is in fluid communication with a firstchamber and a second port in fluid communication with a second chamber.An absorber is in fluid communication with a breathing circuit, theabsorber scrubbing carbon dioxide from the gas directed therein.

The electronic anesthesia delivery apparatus further comprises aninput/output portion having at least one processor in electroniccommunication with said electronic touchscreen display. The first andsecond chambers each having a level sensor and a temperature sensor inelectronic communication with an input/output portion. Theelectronically controlled valves are in electronic communication withthe input/output portion.

According to a second exemplary embodiment, an electronic anesthesiadelivery apparatus comprises a chassis including a first anestheticagent chamber and a second anesthetic agent chamber, each of the firstand second chambers including an anesthetic agent therein. At least oneelectronically controlled valve is in fluid communication with each ofthe first agent chamber and the second agent chamber and an oxygensource. The oxygen source is in fluid communication with each of the atleast one electronically controlled valves. A touchscreen graphicdisplay having controls corresponding to each of the at least oneelectronically controlled valves for controlling flow rate andconcentration of anesthesia.

The electronic anesthesia delivery apparatus includes at least oneelectronically controlled valve in electrical communication with aninput/output portion and the touchscreen graphic display. Thetouchscreen graphic display is utilized to start and stop saidanesthesia delivery apparatus. The touchscreen graphic display indicatesa concentration setting for each of the first anesthetic agent and thesecond anesthetic agent, as well as an oxygen flow rate through theanesthesia delivery apparatus. The touchscreen graphic display furthercomprises an agent level indicator for each of the first and secondchambers and a plurality of controls and gauges for the electronicanesthesia delivery apparatus. The first and second agent chambers arebubbling diffusers.

According to a third embodiment, an electronic anesthesia deliveryapparatus, comprises a chassis comprising first and second anestheticagent chambers. The first and second agent chambers are in fluidcommunication with a plurality of electronically controlled valves. Atouchscreen graphics display is in electronic communication with theelectronically controlled valves. The touchscreen display comprises aplurality of controls for controlling the electronically controlledvalves, the touchscreen display further indicating a oxygen flow rateand concentrations of anesthesia.

The electronic anesthesia delivery apparatus further comprises aninput/output portion in electronic communication with the touchscreengraphic display. The touchscreen graphics display and the electronicallycontrolled valves control concentration and flowrate of at least oneanesthesia. The first and second agent chambers comprise bubblingdiffusers for mixing oxygen and anesthetic agent.

It is also preferable that when a different anesthetic agent isutilized, a chamber which was previously used may be filled with adifferent anesthetic agent and a processor may be programmed with codecontaining an algorithm for controlling a concentration.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front perspective view of a chassis and stand of anexemplary electronic anesthesia delivery apparatus of the presentinvention;

FIG. 2 is a front perspective view of the electronic anesthesia deliveryapparatus of FIG. 1 with various operating components attached;

FIG. 3 is a rear perspective view of the electronic anesthesia deliveryapparatus of FIG. 2 with the rear cover removed;

FIG. 4 is a schematic diagram of the electronic anesthesia deliveryapparatus of FIG. 2;

FIG. 5 is a schematic diagram of the vaporizer utilized with theelectronic anesthesia delivery apparatus of FIG. 2;

FIG. 6 is an electrical block diagram of the electronic anesthesiadelivery apparatus of FIG. 2;

FIG. 7 is a front view of an exemplary touchscreen graphic displayutilized with the present invention; and,

FIG. 8 is a side sectional view of an exemplary anesthetic agent chamberdepicting the diffusion process.

DETAILED DESCRIPTION

Referring now in detail to the drawings, wherein like numerals indicatelike elements throughout the several views, there are shown in FIGS. 1-7various aspects of an electronic anesthesia delivery apparatus whichprovides several advantages over the prior art. First, the novelelectronic anesthesia delivery apparatus utilizes a touchscreen graphicsdisplay to electronically control the delivery of anesthesia, or oxygenor other carrier gas alone, to a patient. Second, the device comprises avaporizer which does not require a wicking material in order to vaporizean anesthetic agent and therefore allows easy conversion from oneanesthetic agent to another. Third, the anesthesia delivery apparatusprovides improved accuracy in controlling anesthesia output over a rangeof oxygen flows. For purpose of the following description, anesthesia ismeant to comprise an anesthetic agent and a carrier gas such as oxygen,air, nitrous oxide or other suitable carrier. For reasons of clarity ofthe present description, the carrier gas is stated to be oxygen.

Referring initially to FIG. 1, a front perspective view of a chassis forthe electronic anesthesia delivery system 10 is depicted. Specifically,the electronic anesthetic delivery apparatus 10 comprises a chassis 12mounted on a stand 14. As depicted, the stand 14 may comprise a verticalleg and a plurality of rollers mounted at a bottom portion of thevertical leg making the electronic anesthetic delivery apparatus 10movable between, for example, operating rooms. Alternatively, the stand14 may comprise a plurality of feet, without wheels, extending from thevertical leg or the chassis 12 may be mounted on a wall in an operatingroom. The chassis 12 comprises an upper housing 16 and a lower housing18. The upper housing 16 is substantially rectangular in shape and mayfurther comprise a box-shaped rear cover (not shown). On the front ofthe upper housing 16 is a window 20 centrally located relative to avertical axis of the upper housing 16. The window 20 receives atouchscreen graphics display 22 discussed further herein.

Still referring to FIG. 1, extending from the upper housing 16 is atleast one anesthetic agent port. The at least one anesthetic agent portis depicted as a first anesthetic agent port 24 and a second anestheticagent port 26. The first anesthetic agent port 24 is utilized to fill acorresponding first chamber 25 (FIG. 3) with a first type of anestheticagent for use during the surgical procedure. The first anesthesia port24 may be color coded or include a sticker of a color corresponding to afirst type of anesthetic agent. The second anesthetic agent port 26 isalso utilized to fill a corresponding second chamber 27 (FIG. 3) with acorresponding second anesthetic agent which may also be utilized duringa surgical procedure. The second anesthetic port 26 may also be colorcoded or have a color coded sticker which corresponds to the secondanesthetic agent utilized for a surgery and to further inhibit use ofthe wrong anesthetic agent. Each of the first and second ports 24,26include a cap to open for filling the chambers and to close once theanesthetic chambers 25,27 are filled.

Referring now to FIGS. 1 and 2, the lower housing 18 is substantiallyrectangular in shape but may comprise alternate shapes. The lowerhousing 18 also comprises a thickness defining an interior volumewherein a plurality of pipes, tubing, fittings or the like are locatedin order to partially define a breathing circuit. Alternatively, thelower housing 18 may be formed of a solid block of material whereinducts defining fluid communication paths may be formed. The lowerhousing also comprises taps for a pop-off valve 30, an inhalation valve32 and an exhalation valve 34, each depicted in FIG. 2. The pop-offvalve 30 provides a relief or bleed valve bleeding off excess gas andcarbon dioxide from the breathing circuit. In fluid communication withthe pop-off valve 30 may be a scavenger system (not shown) defined by,for example, either a charcoal filter or a blower and tubingcombination. The charcoal filter (not shown) may be utilized to removeanesthetic agent from gas bleeding from the pop-off valve 30 into aninterior room of a structure where a surgical procedure is occurring.Alternatively, a blower and tubing combination (not shown) may beconnected to the pop-off valve 30. The upstream side of the blower maybe in fluid communication with the pop-off valve to receive bleed gascomprising anesthesia and carbon dioxide. Further, the blower may forcethe anesthesia and carbon dioxide through an exterior wall of thestructure wherein the procedure is occurring to atmosphere where theanesthesia diffuses.

As previously indicated an inhalation valve 32 and an exhalation valve34 are also disposed on the lower housing 18. The inhalation valve 32may be a check valve which allows flow of anesthesia from the anesthesiadelivery apparatus 10 to the patient in only a single direction. Theexhalation valve 34 may also be a check valve which allows flow ofcarbon dioxide and unconsumed anesthesia back to the lower housing 18for removal of the carbon dioxide, described hereinafter. Also shown onthe lower housing 18 is an inhalation port 33 and an exhalation port 35which connect tubes to the patient. The tubes and ports 33,35 providefluid communication between the patient and the electronic anesthesiadelivery apparatus 10.

The lower housing 18 further comprises a flush valve 40 which provides ahigh flow rate of oxygen through the anesthesia delivery apparatus 10and the components therein in order to clear any residual anesthesia inthe system from a previous surgical procedure. Further the flush valve40 may be used to charge a re-breathing bag 41 which is used to manuallyprovide oxygen to a patient. The flush valve 40 is defined by a poppetvalve (not shown) within the lower housing 18 which is normally closedbut opens when a button 43 on the lower housing 18 is depressed. Theexemplary flush valve 40 provides a flow rate of up to about 50 litersper minute depending on the patient, whereas the normal flow rate ofoxygen through the anesthesia delivery apparatus 10 may be up to about 4liters per minute.

Referring now to FIG. 3, a rear perspective view of the anesthesiadelivery apparatus 10 is depicted with the rear cover removed. A circuitboard 50 is depicted behind the touchscreen graphics display 22. Thecircuit board 50 comprises an input/output portion 87 (FIG. 6) forcommunication with controlling and measuring components, memory and atleast one processor for running algorithms or programs to regulateconcentration of anesthesia. For example the processor may be receivingflow rate and temperature information from at the chambers 25,27 andcompensating to maintain constant percentage output of anesthesia, thusproviding improved control in an electronic manner rather than requiringmanual determinations as in the prior art. One advantage of the presentdevice is that the system is upgradeable for new anesthetic agents byupgrading the processor with algorithms corresponding to vaporization ofthe new drug. Also located on the rear surface of the upper housing 16are first and second chambers 25, 27 corresponding to the firstanesthesia port 24 and second anesthesia port 26, respectively. A fillpipe 29 provides fluid communication between the first anesthesia port24 and the first chamber 25. A second fill pipe (not shown) also extendsbetween the second anesthesia port 26 and the second chamber 27. Thefirst and second chambers 25,27 are sealed pressure vesselssubstantially cylindrical in shape with a hollow interior defining astorage area for anesthetic agent and vaporization of the anestheticagent. The chambers 25,27 further comprise ports which receive oxygeninput from a pressurized source. The ports may be located at the bottomsof the chambers 25,27 in order to best diffuse the anesthetic agenttherein. During operation the oxygen diffuses through the chambers 25,27vaporizing the anesthetic agent and forming a vaporized anesthetic agentwhich is combined with an oxygen flow to define an anesthesia of apreselected concentration. According to the present invention theconcentrations may be adjusted electronically with the touchscreengraphics display 22. Moreover, the circuit board 50 may compriseon-board memory which stores algorithms corresponding to variousanesthetic agents. If a new agent is used, a corresponding algorithmshould be programmed for accurate vaporization of the new anestheticagent.

Also depicted in FIGS. 1-3, is an absorber 38. The absorber 38 is influid communication with the exhaled gas of the patient which containsboth carbon dioxide and unconsumed anesthesia. The carbon dioxide isabsorbed by a plurality of pellets 39 contained within the absorbercanister 38. The pellets 39 may be formed of sodalime material, which iscommercially known as Sodasorb and comprises hydrated lime and sodiumhydroxide. After the carbon dioxide is removed or scrubbed, theunconsumed anesthesia is directed to the inhalation breathing circuitfor delivery to the patient.

Referring now to FIG. 4, a schematic diagram of the anesthesia deliveryapparatus 10 is depicted which generally indicates the flow paths of theelectronic anesthesia delivery apparatus 10. The schematic diagramdepicts an oxygen source 52 in fluid communication with a flow sensor 56and an electronic vaporizer 54. The flow sensor 56 detects flow ofoxygen to the apparatus 10 by comprising a thermistor which detectstemperature changes. For example, when pressurized oxygen flows over thethermistor, the thermistor senses a temperature drop due to the coolertemperature of the pressurized oxygen. However, when the flow stops, thethermistor provides a normal temperature signal which indicates that thepressurized oxygen has stopped flowing. As described further herein,various electronically controlled valves are utilized to control theflow of oxygen between preselected ranges, for example between 0 and 4liters per minute for delivery to the electronic vaporizer 54. Asdescribed further herein, the electronic vaporizer 54 comprises thefirst chamber 25 and the second chamber 27 which allow vaporization ofanesthetic agent by the oxygen supplied by the oxygen source 52 creatinga vaporized anesthetic agent which, in turn, is mixed with oxygen toform anesthesia. Adjacent the vaporizer 54 and flow sensor 56 is theflush valve 40 which is arranged in a bypass configuration so that theoxygen from the oxygen source 52 does not pass through the vaporizer 54and the flow sensor 56 before charging the remaining portions of theanesthesia delivery apparatus 10. As previously indicated the flushvalve 40 is used to charge and clear residual anesthesia or diffusedanesthetic agent remaining within the anesthesia delivery apparatus 10.

Referring still to FIG. 4, once the oxygen passes through the electronicvaporizer 54 and flow sensor 56 the resultant anesthesia enters thelower housing 18, shown in broken lines, which comprises a plurality oftubing, piping, fittings or the like for delivery to and from thepatient as well as ducting between a lower housing and the absorber 38and pop-off valve 30. This movement of anesthesia to and from thepatient defines a breathing circuit between the anesthetic deliveryapparatus 10 and the patient. Specifically, the anesthesia enters thelower housing 18 and moves through a duct to the patient which thepatient inhales through the inhalation check valve 32 (FIG. 3). When thepatient exhales, the exhaled gas comprising carbon dioxide andunconsumed anesthesia passes through the exhalation valve 34. Asindicated in the schematic, the exhaled gas moves in the directionindicated by arrows “A” through ducting in the lower housing 18 to are-breathing bag 41 (FIG. 2) which depends from a stem beneath thepop-off valve 30 FIG. 2. The re-breathing bag 41 captures exhaled gasand further may be manually depressed by a doctor during the surgicalprocedure on the patient in order to provide a breath to the patient.During exhalation, the re-breathing bag 41 becomes filled at which timeremaining exhaled air is directed to the pop-off valve 30 and on to thescavenging system 35. During a subsequent inhalation by the patient, thegas within the re-breathing bag 41 is pulled to the absorber 38indicated by arrow B where remaining carbon dioxide is scrubbed. Thefigure depicts two lines extending between the absorber 38 and there-breathing bag 41 for ease of description and understanding. However,it is well within the scope of the present invention that a single linemay be utilized with two-way flow therein between the absorber 38 andthe re-breathing bag 41. Further, it should be understood by one ofordinary skill in the art that piping may be positioned outside thelower housing 18 and still extend between the indicated components.

Once inside the absorber 38, the carbon dioxide is scrubbed utilizingthe plurality of pellets 39 to remove carbon dioxide from the exhaledgas. The remaining anesthesia is directed from the absorber 38 into thelower housing 18 to the patient for inhalation with the incominganesthesia from the vaporizer 54. Such a system is commonly referred toas a rebreathing system which decreases the amount of wasted anesthesiaand is therefore a more efficient system for use in administeringanesthesia during a surgical procedure. However, it is well within thescope of the present invention that the dual anesthetic chamber andtouchscreen design may be utilized without the rebreathing circuit. Forinstance, in anesthetizing small animals like guinea pigs or mice aphysician may choose not to utilize the rebreathing system because ofthe large volumes of gas stored in the system as compared to the smallrespiratory volume of the animal. Such large volumes vary the responsetime of changes to anesthesia flow which should be precise with suchsmall patients. Thus it should be understood that the anesthesiadelivery apparatus may allow for bypass of the rebreathing circuit.

Also in fluid communication with the lower housing is the pop-off orbleed valve 30 which continually bleeds off exhaled anesthesia. During asurgical procedure gas is continually being added to the breathingcircuit. In order to inhibit pressure build-up, some gas must be bledfrom the system. Thus, the bleed valve 30 is utilized. Since there-breathing bag 41 fills before gas is directed to the bleed valve 30,the bleed valve 30 receives the last portions of exhaled gases from thepatient's lungs. Accordingly, this gas comprises higher concentrationsof carbon dioxide since it is usually the last of the exhaled gases fromthe lungs. This also makes the system more efficient because theabsorber 38 is scrubbing less carbon dioxide and therefore the scrubbingpellets 39 last longer. As previously indicated the pop-off or bleedvalve 30 may be connected to a scavenger system 35 which includes eitheror both of a charcoal filter to scrub anesthesia from the gas beingrelieved at the pop-off valve 30 or a blower and tubing assembly inorder to direct anesthesia from within the interior structure of abuilding to outside the structure for diffusion to atmosphere.

Referring now to FIG. 5, a block diagram is shown indicating flow ofoxygen through the electronic vaporizer 54 indicated by the broken line.Initially oxygen from the oxygen source 52 may pass through a filter 53to remove any impurities over a preselected size, for example, fiftymicron, before moving to the flow sensor 56. Upon leaving the flowsensor 56 the oxygen enters the electronic vaporizer 54 which comprisesthree possible paths for the oxygen. According to the first path whereinthe oxygen diffuses and vaporizes the first anesthetic agent in thefirst chamber 25, the oxygen first flows through a precision orifice 62and then through an electronically controlled valve 60 which is inelectronic communication with the circuit board 50. The orifice 62 issized according to vaporization requirements of the first anestheticagent. Vaporization depends on the type of agent, the temperature of theagent, and the volume of flow into the agent. The precision orifice 62allows regulation of the volume of flow by providing a baseline formaking adjustments and controlling concentrations. As indicated thetouchscreen graphics display 22 may be utilized to open or close thevalve 60 through a selected amount as indicated and selected on thedisplay 22 in order to control the concentration of anesthetic agent.Accordingly, a solenoid or the like may provide for movement of thevalve 60. After passing through the precision orifice 62 the oxygenflows through a first check valve 64 which allows one directional flowto the first agent chamber 25. Alternatively stated, the first checkvalve 64 prevents anesthetic agent from moving upstream from theelectronic vaporizer 54. As depicted in FIG. 8, once in the firstchamber 25, the oxygen moves through a tube to a porous diffusingportion which allows the oxygen to diffuse through the anesthetic agentin a bubble form causing vaporization. As the bubbles diffuse in thefirst anesthetic agent, for example isoflurane, and exit the chamber 25carrying molecules of anesthetic agent, a vaporized anesthetic agent isproduced. The vaporized anesthetic agent is then directed through acheck valve 66 to mix with oxygen and form the anesthesia at theselected concentration. The check valve 66 inhibits anesthesia to flowbackward to the chamber 25. By utilizing the touchscreen graphicsdisplay 22, the first chamber electronic valve 60 selectively controlsoxygen flow causing either intermittent or continual flow to the chamber25 depending on the settings input on the graphics display 22. Duringthis time, oxygen also flows through an electronic valve 80, a precisionorifice 82, and a check valve 84. The pipe in fluid communication withthe valve 80, orifice 82, and check valve 84 is also in fluidcommunication with the pipes comprising the first chamber 25 and thesecond chamber 27 and therefore defines an output for the vaporizer 54.The electronic valve 80 is in electrical communication with the graphicsdisplay 22 in order to open and close the valve 80 and provide a desiredflow rate of oxygen. The valve 80 may include a solenoid to provideopening and closing of valve 80. The diffused anesthetic agent from thefirst chamber 25 and the oxygen mix before exiting the electronicvaporizer 54 and define an anesthesia of a preselected concentrationmeasured as percent anesthetic agent by volume of total oxygen flow.

According to a second flow path, the oxygen may flow through a secondelectronically controlled valve 70 in order to pass through the secondchamber 27. Like the first electronic valve 60, the secondelectronically controlled valve 70 is in electrical communication withthe circuit board 50 and therefore may be controlled by the touchscreengraphics display 22. Such control also allows the valve 70 to be openedor closed according to the concentration of anesthesia required duringthe surgical procedure. Once the electronically controlled valve 70 isopened the oxygen passes through the precision orifice 72 and to thevalve 70. As previously indicated, the precision orifice 72 is sizedaccording to the dimensions required for vaporization of the anestheticagent. After passing through the valve 70 the oxygen then passes to thesecond chamber 27. The second chamber 27 may include, for instance,sevoflurane which may commonly be utilized with isoflurane during asurgical procedure. After the oxygen bubbles through the second chamber27 and is diffused in order to produce a diffused anesthetic agent, thediffused agent passes through a check valve 76 and mixes with oxygenpassing through valve 80 to form an anesthesia. The check valve 76 alsoinhibits back flow to the second chamber 27. The anesthesia passes fromthe electronic vaporizer 54 at a preselected concentration measured aspercent by volume and indicated on the graphics display 22.Alternatively, both the first valve 60 and the second valve 70 areopened in order to allow diffused anesthetic agent to be produced fromboth the first chamber 25 and the second chamber 27. Such configurationis desirable when both chambers comprise the same anesthetic agent or iftwo agents need to be mixed for use during a surgical procedure.

According to a third possible flow path, pure oxygen may be administeredto a patient prior to a surgical procedure to saturate the patient'sbody with oxygen. According to an alternate scenario, the pure oxygenmay be administered following the surgical procedure in order to bringthe patient out from the anesthetic effects. In order to provide pureoxygen to a patient, the electronically controlled valves 60,70 areclosed and the electronically controlled valve 80 is opened to aselected flow rate, as indicated on the graphics display 22. In fluidcommunication with the electronically controlled valve 80 is an orifice82 and a check valve 84 which all direct flow from the oxygen source tothe lower housing 18 and on to the patient. As shown in FIG. 5, byclosing valves 60, 70 and opening valve 80, only oxygen is output fromthe vaporizer 54. It should be understood that the various signals sentto the electronically controlled valves 60,70, 80 may be part offeedback control loops in order to control the dynamic behavior of thesystem. In addition, such a feedback control loop allows better accuracyin maintaining constant output percentage of anesthesia.

Referring now to FIG. 6, an electrical block diagram generally indicatesthe various electrical connections utilized in the electronic anesthesiadelivery apparatus 10. The circuit board 50 (FIG. 3) comprises aninput/output (I/O) portion 87 comprising a plurality of inputs andoutputs with various components of the electronic anesthesia deliveryapparatus 10. The I/O portion 87 of the circuit board 50 provides asignal to an inverter 22 a which operates a back light (not shown) forthe touchscreen graphics display 22. Specifically the inverter 22 asteps up the 5 volt DC signal to a several hundred volts in order toilluminate a backlight for the graphics display 22. The I/O portion 87also provides a signal to a display controller board 23 based on signalsinput from various other measuring and signal components incommunication with the I/O portion 87. The display controller board 23comprises a video card and flash memory to produce the graphicaluser-interface which indicates the operating conditions and parameters,however various components may be utilized to produce graphicaluser-interface on the graphics display 22. The signal received from theI/O portion 87 is graphically produced on the display 22 by the displaycontroller board 23.

The first and second chambers 25,27 comprise sensors which are inelectrical communication with the I/O portion 87. The first chamber 25and the second chamber 27 each comprise a temperature sensor (not shown)which sends a temperature signal 63 to the I/O portion 87. Thetemperature sensor measures the agent temperature and is importantbecause the anesthetic agent changes temperature during vaporization.This temperature change affects further vaporization and must becompensated for. Such compensation is made by algorithms on the circuitboard 50 for instance by a processor or microprocessor. Accordingly, atemperature measurement must be made.

In addition to the temperature signals delivered to the I/O portion 87,an agent level signal 65 is also delivered from the first and secondchambers 25,27. As described further, the touchscreen graphics display22 indicates the amount of anesthetic agent in each of the first andsecond chambers 25,27. According to one embodiment a capacitance sensormay be utilized to provide a signal to the I/O portion 87. With theagent level signal 65 received from the capacitance sensors the levelsof the chambers 25,27 are visually indicated on the display 22. Thisprevents running out of anesthetic agent during a surgical procedure.

The I/O portion 87 also receives a signal from an apnea adapter 89 whichcomprises a thermistor positioned in the breathing passageway of thepatient. The adapter 89 sends a signal based on temperature differencesmeasured when the patient breathes. For example, the temperature willraise during exhalation and will drop during inhalation. If the I/Oportion 87 fails to receive a signal from the apnea adapter 89 within apreselected time period, the processor concludes that the patient is notbreathing properly and an alarm may sound from a speaker 90.

The I/O portion 87 may also receive a signal from a remote infraredreceiver 91. The electronic anesthesia delivery apparatus 10 may alsocomprise a remote control or transmitter 93 which sends an infraredsignal to the remote infrared receiver 91 which in turn communicateswith the I/O portion 87. The remote control 93 may communicate with thereceiver 91 to increase or decrease oxygen flow rates by controllingvalve 80 or increase or decrease flow rates of oxygen through the firstand second chambers 25,27 thereby controlling rates of vaporization andtherefore concentrations of anesthetic agent in anesthesia.

The I/O portion 87 also receives a signal from a breathing circuitpressure sensor 92. The breathing circuit pressure sensor 92 is alsomeasured at the breathing passageway of the patient and is utilized tomeasure the breathing pressure of the circuit so as not to harm thepatient and further to insure enough pressure is present to deliveranesthesia to the patient. If the breathing circuit pressure fallsoutside a preselected range the signal may cause an alarm which notifiesa physician through the speaker 90.

The I/O portion 87 also receives a signal from the flow sensor 56indicating flow of oxygen into the electronic vaporizer 52. If the flowsensor 56 sends a signal that flow is not available, an alarm may soundthrough the speaker 90 indicating to a user that the condition should becorrected.

The apparatus also comprises AC or DC power capability. The device mayreceive AC power from 110 or 230 volt source. Alternatively, the devicemay be operated from a DC battery power supply. IN addition to thesepower sources, the device 10 may further comprise a battery backup in anAC power supply is lost during a surgical procedure.

Referring now to FIG. 7, a front view of the touchscreen graphicsdisplay 22 is shown which comprises the graphical users interface. Theinterface depicted on the display 22 allows the user to control variouscomponents of the electronic anesthesia delivery apparatus 10. At theupper left hand corner of the display 22 is a real time clock 100 whichmay display 12-hour time or 24-hour time as depicted. Adjacent the realtime clock 100 is an agent identification (ID) window 102 whichindicates “None”. By pressing the agent ID window 102 and the up/downtoggles 106, 108, the agent ID toggles through the selections “None”,the first anesthetic agent, for example “Isoflurane”, and the secondanesthetic agent, for example “Sevoflurane”. The window 102 may alsochange color according to the corresponding color code for the drugindicated. When the first anesthetic agent is displayed in the agent IDwindow 102, the toggles 106,108 are utilized to control concentrationsof that anesthetic agent. Alternatively, when the second anestheticagent is highlighted in the agent ID window 102 the toggles 106,108 areutilized control changes to the second anesthetic agent. Thus, thetoggles 106, 108 control movement of the electronic control valves 60,70thus varying the concentration of the diffused anesthetic agent. Bypressing the agent ID button 102 again, the ID returns to “None” asdepicted. Thus the user presses the agent ID window 102 and togglesthrough the selections until the desired agent may be controlled.

Beneath the clock 100 and the agent ID 102 is a virtual concentrationsetting 104 which depicts a percent by volume of an agent which ishighlighted in the agent ID window 102. For example, when the firstanesthetic agent is highlighted in the agent ID window 102, theconcentration of the first anesthetic agent is shown in theconcentration setting 104. The same condition occurs when the secondanesthetic agent is highlighted in the agent ID window 102. When adesired agent is selected, the corresponding concentration setting 104may be adjusted for that anesthetic agent. The concentration beingoutput for each anesthetic agent 104 is measured in percent ofanesthetic agent by volume and may range, for example, up to about 10percent.

Beneath the concentration setting 104 is a digital pressure gauge 110which records pressure within the breathing system. As depicted, thedigital gauge 110 is circular in shape with a digital needle indicatingthe pressure within the breathing system. The digital pressure gauge 110receives a signal via the I/O portion 87 from the breathing circuitpressure sensor 92 (FIG. 6). As previously indicated, the breathingcircuit pressure sensor 92 (FIG. 4) is located as close to the patientas possible obtain accurate readings of pressure at the patient. Thegauge 110 is shown indicating pressure in centimeters of water.

Along the left hand side of the touchscreen graphics display 22 is avirtual first level indicator 114 for the first anesthetic agent in thefirst chamber 25. The first level indicator 114 receives a signal viathe I/O portion 87 from the agent level signal 65 (FIG. 6). Byindicating the level of agent in the first chamber 25, the user knowswhen a refill of anesthetic agent is necessary prior to starting aprocedure. This is particularly useful so that a chamber does not emptyduring a procedure which would require refilling and could harm thepatient. On the right hand side of the touchscreen display 22 is avirtual second level indicator 116 which indicates the level of secondanesthetic agent in the second chamber 27. The first and second levelindicators 114,116 may both include bars indicating agent levels or mayinclude virtual moving indicators which move along a level bar asdepicted.

Beneath the pressure gauge 110 is an octagonal shape which indicates astop button 112 for the anesthesia delivery apparatus 10. The stopbutton 112 is pressed when a procedure is finished and the anesthesiadelivery is no longer needed. The stop button 112 may be colored red onthe display 22 which is commonly recognized as a stop signal. Alsobeneath the breathing pressure gauge 110 is a case clock 118 which maybe used by a physician to bill for time on a particular surgicalprocedure or to bill for amount of anesthesia utilized. The case clock118 may be stopped by pressing the stop button 112, thus marking thetime of the surgical procedure.

In the middle of the touchscreen display 22 is a virtual oxygen flowmeter which receives a signal from a flowmeter and indicates the totalflow of oxygen being delivered from the electronic vaporizer 54.Although various flow rates may be utilized, the present exemplaryembodiment comprises a design which delivers up to 4 liters of oxygenper minute. At a lowermost position of the oxygen flowmeter 120 is astart button 122 which starts oxygen flow to the patient to begin aprocedure. The start button 122 may be colored green to indicate a startfunction to a user. Once the button 122 is depressed, the oxygen flowmay be increased using toggle button 108 or decreased using togglebutton 106 as will be indicated on the flowmeter 120. The toggle buttons106,108 are therefore controlling the electronic control valve 80 inorder to vary the oxygen flow through the system.

Also shown on the touchscreen graphics display 22 is an alarm or warningscreen 124. The alarm screen 124 provides a visual indication to a userthat an alarm condition has been triggered. For instance, the apneaadapter 89 may be triggered by a lack of breath from the patient after apreselected amount of time, or the flow sensor 56 may cause an alarm ifoxygen from the source 52 is not flowing. Thus, in addition to theaudible alarm signal provided by the speaker 90, the alarm screen 124may provide a visual indication of an alarm condition which should becorrected.

Beneath the alarm screen 124 is a configuration button 126 which allowsa user to configure various settings, alarm conditions and the like.Adjacent the configuration button 126 is an mute or override button 128which silences the audible alarm for a preselected period of time. Forexample, if an alarm sounds a user may press the override button 128which cancels the audible alarm from speaker 90 for an adjustable timeperiod of, for example, 2 minutes. This muted time period is also aperiod which may be set utilizing the configuration button 126. After,the two minute period, if the alarm condition is not corrected, thealarm will sound again.

Alternatively to the touchscreen graphical display 22, a plurality ofdevices may be utilized. For instance, a graphics screen such as an LCDor CRT monitor may be used in combination with a separate touchpad orkeypad programmed for use with the anesthesia device. Further, atrackball or mouse-type pointing device may be utilized with the displayto make selections and adjustments to the system. Accordingly, suchembodiments should be understood to be within the scope of the presentdisclosure.

In operation a carrier gas source, for example a 50 psi oxygen source,is connected to an inlet port. The anesthesia delivery apparatus 10 isconnected to an A/C power source and powered on. Initially, variouselectronics and components of the apparatus 10 will go through aself-test to verify proper function. The alarm screen 124 will displaythe progress of this test and pass/fail information will be posted. Ifany component fails the unit will be put in permanent failsafe mode orfor some non-critical test the user can continue by pressing an overridemode key (not shown) or key combination. Alternatively, when theself-test is successfully completed the apparatus 10 will go into readystatus waiting on user input.

Next the physician or an assistant can connect their external disposablebreathing hoses to the patient and the ports 33,35. The physician nexttouches the virtual oxygen flow control start button 122 at which timethe virtual flowmeter 120 will become highlighted or illuminatedindicating the microprocessor is ready for increments or decrements toset the flowrate. The physician increases the flow to a desired settingby pressing the up toggle 108. Next the apparatus begins immediatelydelivering oxygen upon selection of an oxygen flow greater than 0. Thecase clock 118 begins timing when the oxygen flow begins.

Once the correct oxygen flow is achieved the user then touches theanesthetic agent selection box 102. This will highlight. The physicianwould then press the up or down arrows to cycle through the selectionsof the first anesthetic agent, for example isoflurane, the secondanesthetic agent, for example sevoflurane, and the none selection. Otherdrugs or drugs developed in the future may be programmed into thesystem. Once the desired anesthetic agent is displayed, the physiciantouches the concentration setting window 104 to select the outputconcentration of agent desired. The window 104 will highlight and thephysician uses the toggles 106,108 to select the percentage of agent.Next the anesthesia begins delivery upon choosing a percentage greaterthan 0.

During operation the virtual pressure gauge 110 displays the patientlung pressures being realized. Sensors monitor these pressures as wellas breath detections, agent percentage settings and many other safetyrelated parameters. If any of the sensors detect an unsafe condition, analarm may sound. At anytime the physician can adjust the carrier gasflow settings or by pressing the stop button 112 on the display 22 cancease all flows and stop the case clock. By pressing the stop button 112the delivery apparatus 10 “ends the case” and is put into standby mode.By pressing anywhere on the display 22 the unit can be re-activated andready for input. The override or mute virtual button 128 may be pressedto silence the alarms for 2 minutes. Further, alarm conditions aredisplayed on the alarm screen 124. The unit is intended to be left onand go into a sleep mode however, the physician or an assistant may turnoff and on each day if they desire.

The foregoing description of several methods and an embodiment of theinvention have been presented for purposes of illustration. It is notintended to be exhaustive or to limit the invention to the precise stepsand/or forms disclosed, and obviously many modifications and variationsare possible in light of the above teaching. It is intended that thescope of the invention be defined by the claims appended hereto.

1. An electronic anesthesia delivery apparatus, comprising: a chassiscomprising at least one anesthetic vaporizer; a carrier gas input portin flow communication with said at least one anesthetic vaporizer; saidvaporizer having an inlet in flow communication with said carrier gasinput port, a precision orifice downstream of said inlet and anelectronic control valve downstream of said precision orifice, said atleast one anesthetic vaporizer having a chamber wherein a liquidanesthetic agent is disposed, said chamber being downstream of saidelectronic control valve, a carrier gas conduit extending into saidchamber beneath an upper level of said liquid anesthetic agent, saidchamber having an outlet port disposed above said upper level of saidliquid anesthetic agent, wherein a carrier gas passes through a porousdiffusing portion at an end of said carrier gas conduit and bubblesthrough said liquid anesthetic agent forming an anesthetic gas in fluidcommunication with said outlet port of said chamber; an electronictouchscreen display mounted to said chassis for controlling a carriergas flow rate to said at least one anesthetic vaporizer andconcentration of said anesthetic gas delivered to a patient; a circuitboard having an input/output portion, said electronic touchscreendisplay in electronic communication with said circuit board, atemperature signal received by said input/output portion indicatingtemperature of said anesthetic agent, said circuit board further inelectronic communication with said electronic control valve tointermittently open and close the electronic control valve in automatedfashion in order to vary said carrier gas flow rate through saidchamber, said carrier gas flow rate being used in combination with saidtemperature signal to control a rate of vaporization and concentrationof said anesthetic agent in said anesthetic gas; a bleed valve in fluidcommunication with a re-breathing circuit, said valve having at leastone closed position to open said re-breathing circuit and direct exhaledgas to an absorber which scrubs carbon dioxide and allows re-breathingof anesthetic, said valve having at least a second open position toclose said re-breathing circuit and to direct said exhaled gas toatmosphere.
 2. The electronic anesthesia delivery apparatus of claim 1,said electronic anesthesia delivery apparatus partially defining abreathing circuit.
 3. The electronic anesthesia delivery apparatus ofclaim 2, said electronic anesthesia delivery apparatus and said patientdefining a breathing circuit.
 4. The electronic anesthesia deliveryapparatus of claim 1 further comprising a carrier gas source in fluidcommunication with said carrier gas input port of said anesthesiadelivery apparatus.
 5. The electronic anesthesia delivery apparatus ofclaim 4 further comprising electronically controlled valves selectivelycontrolling flow of said carrier gas from said carrier gas source to afirst and second chambers.
 6. The electronic anesthesia deliveryapparatus of claim 1 further comprising a first port in fluidcommunication with a first chamber and a second port in fluidcommunication with a second chamber.
 7. The electronic anesthesiadelivery apparatus of claim 1 further comprising an absorber in fluidcommunication with a breathing circuit, said absorber scrubbing carbondioxide from the gas directed therein.
 8. The electronic anesthesiadelivery apparatus of claim 1 further comprising an input/output portionhaving at least one processor in electronic communication with saidelectronic touchscreen display.
 9. The electronic anesthesia deliveryapparatus of claim 8, further comprising first and second chambers eachhaving a level sensor and a temperature sensor in electroniccommunication with an input/output portion.
 10. The electronicanesthesia delivery apparatus of claim 8 further comprisingelectronically controlled valves in electronic communication with saidinput/output portion.
 11. An electronic anesthesia delivery apparatus,comprising: a chassis comprising a first anesthetic agent vaporizerchamber and a second anesthetic agent vaporizer chamber, each of saidfirst and second vaporizer chambers comprising an anesthetic agenttherein; at least one electronically controlled valve in fluidcommunication with each of said first agent vaporizer chamber and saidsecond agent vaporizer chamber and a carrier gas source, said at leastone electronically controlled valve being automatically intermittentlyactuated to vary flow rate of a carrier gas through each of said firstanesthetic agent vaporizer chamber and said second anesthetic agentvaporizer chamber; said carrier gas source in fluid communication witheach of said at least one electronically controlled valves; a precisionorifice in flow communication with said carrier gas source and said atleast one electronically controlled valve; each of said first and secondagent vaporizer chambers containing a liquid anesthetic agent thereinand an inlet conduit extending into said liquid anesthetic agent andhaving a porous diffusing portion at an end of said inlet conduit, saidcarrier gas passing from said carrier gas source through said conduitand said porous diffusing portion and diffusing through said liquidanesthetic agent to vaporize said liquid anesthetic agent forminganesthesia of desired concentration by the automated intermittentactuation of said at least one electronically controlled valve, saidchamber having an outlet port above an uppermost liquid level and influid communication with said anesthesia; a touchscreen graphic displaycomprising controls corresponding to each of said at least oneelectronically controlled valves for controlling flow rate andconcentration of anesthesia; a breathing circuit having a valve, saidvalve having at least one position to open said breathing circuitbetween said electronic anesthesia delivery apparatus and a patientwherein exhaled gas from said patient is diffused to atmosphere, and atleast a second position to close said breathing circuit between saidelectronic anesthesia delivery apparatus and said patient wherein gasexhaled from said patient is scrubbed and anesthesia is re-breathed;and, a circuit board having an input/output portion, said touchscreengraphic display in electronic communication with said circuit board, atemperature signal indicating temperature of said anesthetic agent, saidtemperature signal received by said input/output portion, said circuitboard further in communication with said at least one electronicallycontrolled valve to vary the intermittent actuation and said carrier gasflow rate so that said at least one electronically controlled valve isused in combination with said temperature signal to control a rate ofvaporization and concentration of said anesthetic agent in saidanesthesia.
 12. The electronic anesthesia delivery apparatus of claim11, said at least one electronically controlled valve in electricalcommunication with an input/output portion and said touchscreen graphicdisplay.
 13. The electronic anesthesia delivery apparatus of claim 12,said touchscreen graphic display being utilized to start and stop saidanesthesia delivery apparatus.
 14. The electronic anesthesia deliveryapparatus of claim 11, said touchscreen graphic display indicating aconcentration setting for each of said first anesthetic agent and saidsecond anesthetic agent.
 15. The electronic anesthesia deliveryapparatus of claim 11, said touchscreen graphic display indicating acarrier gas flow rate through said anesthesia delivery apparatus. 16.The electronic anesthesia delivery apparatus of claim 11, saidtouchscreen graphic display comprising an agent level indicator for eachof said first and second agent vaporizer chambers.
 17. The electronicanesthesia delivery apparatus of claim 11, said touchscreen graphicdisplay comprising a plurality of controls and gauges for saidelectronic anesthesia delivery apparatus.
 18. The electronic anesthesiadelivery apparatus of claim 11, said first and second agent vaporizerchambers being bubbling diffusers.
 19. An electronically controlledmultiple anesthesia delivery apparatus, comprising: a chassis comprisingfirst and second anesthetic agent chambers; a carrier gas supply influid communication with said first and second chambers; a precisionorifice in flow communication with said carrier gas supply and saidfirst and second chambers; a touchscreen graphic display comprising avirtual carrier gas flow_rate indicator which is utilized to increase ordecrease carrier gas flow_rate; a virtual concentration indicatordisplayed on said touchscreen graphic display; virtual controls forcontrolling concentration of said anesthesia on said touchscreengraphics display; said first and second anesthetic agent chambers havinga first and second liquid anesthetic agent therein respectively, aninlet tube having a porous diffusing portion at a lowermost end of saidinlet tube at bottoms of said first and second agent chambers and influid communication with said carrier gas supply, said inlet tube andsaid porous diffusing portion disposed beneath an uppermost level ofsaid liquid anesthetic agent allowing bubbling of said carrier gasthrough said first and second anesthetic agents, respectively to createfirst and second anesthesias, an outlet port within each of said firstand second agent chambers above said uppermost level of said liquidanesthetic agents, said outlet port in fluid communication with saidanesthesia; a circuit board having an input/output portion, saidtouchscreen graphic display in electronic communication with saidcircuit board, a temperature signal indicating temperature of saidanesthetic agent received by said input/output portion, said circuitboard further in communication with an electronically controlled valvewhich controls said carrier gas flow rate by automated intermittentactuation of said electronically controlled valve by said circuit board,said carrier gas flow rate being used in combination with saidtemperature signal to control a rate of vaporization and concentrationof said anesthetic agent in said anesthetic gas; and, a re-breathingcircuit having a valve, said valve having at least at least a firstposition to allow re-breathing of exhaled gas including at least one ofsaid first and second anesthetic agents and a second position to allowdiffusion of said at least one of said first and second anestheticagents to atmosphere.
 20. An electronically controlled multipleanesthesia delivery apparatus, comprising: a chassis comprising firstand second anesthetic agent vaporizer chambers; said first and secondagent vaporizer chambers in fluid communication with a plurality ofelectronically controlled valves; a touchscreen graphics display inelectronic communication with said electronically controlled valves;said touchscreen graphics display comprising a plurality of controls forcontrolling said electronically controlled valves, said touchscreengraphics display further indicating a carrier gas flow rate andconcentrations of anesthesia; a precision orifice in fluid communicationwith said first and second vaporizer chambers; said vaporizer chambershaving an inlet tube extending into first and second liquid anestheticagents within said first and second vaporizer chambers respectively,said vaporizer chambers further comprising an outlet port disposed abovesaid liquid anesthetic agents and in fluid communication with first andsecond anesthesias, said first and second inlet tubes having a porousdiffusing portion at ends and within said first and second anestheticagents for carrier gas to bubble through said first and secondanesthetic agents, respectively to create said first and secondanesthesias; a circuit board having an input/output portion, saidtouchscreen graphic display in electronic communication with saidcircuit board, a temperature signal indicating temperature of saidanesthetic agent received by said input/output portion, said circuitboard further in communication with a receiver which controls saidplurality of electronically controlled valves and said carrier gas flowrate, each of said electronically controlled valves in electroniccommunication with said circuit board wherein said circuit boardautomatically controls intermittent opening and closing of saidelectronically controlled valves to vary flow rate of said carrier gasthrough said vaporizer chambers, said carrier gas flow rate also beingused in combination with said temperature signal to control a rate ofvaporization and concentration of said anesthetic agent in said firstand second anesthesias; a breathing circuit and a re-breathing circuitin flow communication; and, a valve disposed between said breathingcircuit and said re-breathing circuit, said valve having a firstposition to open said flow communication allowing scrubbing of exhaledgas and re-breathing of anesthesia, said valve having a second positionto close said flow communication between said re-breathing circuit andallow diffusion of said exhaled gas to atmosphere.
 21. The electronicanesthesia delivery apparatus of claim 20, said touchscreen graphicsdisplay and said electronically controlled valves controllingconcentration and flowrate of at least one anesthesia.
 22. Theelectronic anesthesia delivery apparatus of claim 20 further comprisingan input/output portion in electronic communication with saidtouchscreen graphic display.
 23. The electronic anesthesia deliveryapparatus of claim 20, said first and second agent vaporizer chamberscomprising bubbling diffusers for mixing a carrier gas and anestheticagent.
 24. An electronic anesthesia delivery apparatus, comprising: achassis comprising first and second vaporizing chambers; said first andsecond vaporizing chambers diffusing a carrier gas through first andsecond anesthetic agents in liquid form; a carrier gas source in flowcommunication with a precision orifice and said first and secondvaporizing chambers, said first and second vaporizing chambers eachhaving a tube extending into said first and second anesthetic agents andin fluid communication with said carrier gas source, said tubes eachhaving porous diffusing portions at an end for bubbling said carrier gasthrough said first and second vaporizing chambers to form anesthesia,said first and second chambers further comprising an outlet portdisposed above said first and second anesthetic agents and in fluidcommunication with said vaporized anesthesia; an electronic touchscreendisplay mounted to said chassis for controlling a carrier gas flow rateto said at least one anesthetic vaporizer and concentration ofanesthetic gas delivered to a patient; a circuit board having aninput/output portion, said input/output portion controlling at least oneelectronically controlled valve, said input/output portion controllingautomatic intermittent actuation of said at least one electronicallycontrolled valve in order to control said gas flow rate electronically,a temperature signal received by said input/output portion, saidtemperature signal utilized with said gas flow rate to varyconcentration of anesthetic agent in anesthesia; and, a valve having atleast an open position and a closed position, said open positionallowing flow communication of a patient's exhaled gas to atmosphericdiffusion, said closed position opening a re-breathing circuit allowingsaid exhaled gas to pass through an absorber for re-breathing of saidanesthesia.